The first mention of Graville Abbey was in the 9th century. Considered to be a masterpiece of the Romanesque art in Normandy, the abbey underwent several periods of construction since the 11th century. The church's nave and transept date from the Romanesque period. Guillaume Malet de Graville, who was victorious during the Hastings battle alongside William the Conqueror, as well as his descendants, invested their fortune in preserving the riches of this monument. Today conventual buildings are converted to a museum.
References:The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.